Damped transverse oscillations of interacting coronal loops

Damped transverse oscillations of magnetic loops are routinely observed in the solar corona. This phenomenon is interpreted as standing kink magnetohydrodynamic waves, which are damped by resonant absorption owing to plasma inhomogeneity across the magnetic field. The periods and damping times of these oscillations can be used to probe the physical conditions of the coronal medium. Some observations suggest that interaction between neighboring oscillating loops in an active region may be important and can modify the properties of the oscillations compared to those of an isolated loop. Here we theoretically investigate resonantly damped transverse oscillations of interacting non-uniform coronal loops. We provide a semi-analytic method, based on the T-matrix theory of scattering, to compute the frequencies and damping rates of collective oscillations of an arbitrary configuration of parallel cylindrical loops. The effect of resonant damping is included in the T-matrix scheme in the thin boundary approximation. Analytic and numerical results in the specific case of two interacting loops are given as an application.Comment: Accepted for publication in A&

Reactive nitrogen in the Spanish agri-food sector: environmental impact on atmosphere, soils, water and resources.

The presence of reactive species of nitrogen (N) in the biosphere might cause environmental impacts at local, regional and global scales. Nowadays the N flows generated by human activities greatly exceed natural processes, thus a necessity exists of identifying and quantifying the current state of environmental N loads. The aim of this work is to quantify the amount of reactive N used in the Spanish agri-food sector, assessing the related potential environmental impacts and potential uses of resources. Data from a previously calculated N flow analysis in the Spanish agricultural and food production system for the 1996-2000 time period were used. Total anthropogenic N inputs to the systems were calculated. Input and output flows were considered in each economic compartment in order to calculate use efficiency (ratio of useful outputs to total inputs), eco-efficiency (ratio of useful outputs to outputs to the environment) and recycling rate (ratio of flow recycled to an earlier life-cycle compartment divided by total outputs). Environmental impacts were assessed by quantifying the N balance between the economic and the environmental subsystems: water, atmosphere, ecosystems soils and other soils. In this case agricultural soils were also considered an environmental compartment, since they are an important intermediate path to the environment. The impact on resources was evaluated considering the net N imports into the system and legume fixing crops, pastures and forages versus feed and fertilizers within the system. Anthropogenic N inputs are relatively high in Spain, which is a net importer of nitrogen, mainly in fertilizers and food and feed commodities. Environmental compartments receive relative high amounts of reactive nitrogen, especially soils. Furthermore, there was a relative low use of domestic resources, with a low proportion of N recycled within the system

About the Infinite Repetition of Histories in Space

This paper analyzes two different proposals, one by Ellis and Brundrit, based on classical relativistic cosmology, the other by Garriga and Vilenkin, based on the DH interpretation of quantum mechanics, both of which conclude that, in an infinite universe, planets and living beings must be repeated an infinite number of times. We point to some possible shortcomings in the arguments of these authors. We conclude that the idea of an infinite repetition of histories in space cannot be considered strictly speaking a consequence of current physics and cosmology. Such ideas should be seen rather as examples of {\guillemotleft}ironic science{\guillemotright} in the terminology of John Horgan.Comment: 14 pages, no figures. Accepted for publication in slightly different form at THEORIA (http://www.ehu.es/ojs/index.php/THEORIA

The future obligations of "project manager" as construction integral director (DIPE) in the law of buildings construction in spain (LOE)

In the year 1999 approves the Law of Construction Building (LOE, in Spanish) to regulate a sector such as construction, which contained some shortcomings from the legal point of view. Currently, the LOE has been in force 12 years, changing the spanish world of the construction, due to influenced by internationalization. Within the LOE, there regulating the different actors involved in the construction building, as the Projects design, the Director of Construction, the developer, The builder, Director of execution of the construction (actor only in Spain, similar as construcion engineer and abroad in), control entities and the users, but lacks figure Project manager will assume the delegation of the promoter helping and you organize, direct and management the process. This figure assumes that the market and contracts are not legally regulated in Spain, then should define and establish its regulation in the LOE. (Spain Construction Law) The translation in spanish of the words "Project Manager is owed to Professor Rafael de Heredia in his book Integrated Project Management, as agent acting on behalf of the organization and promoter assuming control of the project, ie Integraded Project Management . Already exist in Spain, AEDIP (Spanish Association Integrated of Project Construction management) which comprises the major companies in “Project Management” in Spain, and MeDIP (Master in Integrated Construction Project) the largest and most advanced studies at the Polytechnic University of Madrid, in "Construction Project Management" they teach which is also in Argentina. The Integrated Project ("Project Management") applied to the construction process is a methodological technique that helps to organize, control and manage the resources of the promoters in the building process. When resources are limited (which is usually most situations) to manage them efficiently becomes very important. Well, we find that in this situation, the resources are not only limited, but it is limited, so a comprehensive control and monitoring of them becomes not only important if not crucial. The alternative of starting from scratch with a team that specializes in developing these follow directly intervening to ensure that scarce resources are used in the best possible way requires the use of a specific methodology (Manual DIP, Matrix Foreign EDR breakdown structure EDP Project, Risk Management and Control, Design Management, et ..), that is the methodology used by "Projects managers" to ensure that the initial objectives of the promoters or investors are met and all actors in process, from design to construction company have the mind aim of the project will do, trying to get their interests do not prevail over the interests of the project. Among the agents listed in the building process, "Project Management" or DIPE (Director Comprehensive building process, a proposed name for possible incorporation into the LOE, ) currently not listed as such in the LOE (Act on Construction Planning ), one of the agents that exist within the building process is not regulated from the legal point of view, no obligations, ie, as is required by law to have a project, a builder, a construction management, etc. DIPE only one who wants to hire you as have been advanced knowledge of their services by the clients they have been hiring these agents, there being no legal obligation as mentioned above, then the market is dictating its ruling on this new figure, as if it were necessary, he was not hired and eventually disappeared from the building process. As the aim of this article is regular the process and implement the name of DIPE in the Spanish Law of buildings construction (LOE

Validación de los instrumentos “cuestionario de enfoques de aprendizaje y cuestionario de enfoques de enseñanza” traducidos y adaptados para caracterizar los enfoques en estudiantes y profesores de ciencias en el contexto colombiano

Siendo los enfoques de aprendizaje y de enseñanza, constructos de gran relevancia para el interés investigativo de quien escribe este documento; en el mismo se describen los instrumentos originales que han sido desarrollados en idioma inglés para ser aplicados en países del Reino Unido, Suecia, Australia y China entre otros, para caracterizar estos enfoques. También se describen las etapas seguidas para su validación, luego de haber sido traducidos y adaptados al contexto Colombiano. Se concluye que los instrumentos son aceptables para ser utilizados posteriormente en investigaciones que utilicen los datos que proporcionan, para establecer relaciones con diversas variables relativas a la enseñanza de las ciencias, en procura de ampliar su frontera de conocimientos